Automatic analyzers such as an automatic biochemical analyzer and an automatic immunoassay analyzer, for example, have a washing tank for washing a probe with washing water after the suction and discharge of a reagent or a target specimen sample.
In general, the range of contamination of a probe during the suction of a reagent or a target specimen sample with the probe is about 5 mm, which is the depth to which the probe's tip is thrust into the liquid after detecting the liquid surface, and the range is the washing range of the probe. However, for example, when the reagent is suctioned from a reagent bottle which is covered with a cap with a cut to prevent the evaporation of the reagent, it is necessary to wash the range of the probe which corresponds to the range from the cap of the reagent bottle to the bottom of the reagent bottle. Thus, the range to be washed should be enlarged.
However, when the washing range of the nozzle is enlarged, a longer washing period should be provided. Also, after the probe is washed, a large amount of washing water remains on the surface of the probe. When the next reagent is suctioned with the probe in this state, it is supposed that the washing water remaining on the probe surface contaminates the reagent bottle, and the reagent is sometimes diluted with the washing water. Also in case in which the probe is thrust deep into the target specimen sample, the same problem arises when a broad range of the probe is washed.
Accordingly, when the washing range of the probe is broad (for example, when the washing range is 80 mm from the tip), a method for removing the washing water remaining on the probe surface by moving the probe to the position of a vacuum-suction tube after washing the probe at a probe-washing position, lowering the probe into the vacuum-suction tube and creating a vacuum in the vacuum-suction tube is known as a method for removing the washing water remaining on the probe surface after washing the probe.
However, to increase the speed of the apparatus or to minimize the installation space of the washing tank, methods in which operations of from washing of the probe to drying of the probe are conducted in a single washing tank are known (see PTLs 1, 2 and 3).